Metadata Report for BODC Series Reference Number 442732


Metadata Summary

Data Description

Data Category Offshore sea floor pressure series
Instrument Type
NameCategories
Aanderaa WLR 5 Water Level Recorder  sea level recorders; water temperature sensor
Instrument Mounting fixed benthic node
Originating Country United Kingdom
Originator -
Originating Organization Proudman Oceanographic Laboratory (now National Oceanography Centre, Liverpool)
Processing Status banked
Project(s) Land Ocean Interaction Study (LOIS)
LOIS Shelf Edge Study (LOIS - SES)
 

Data Identifiers

Originator's Identifier wr0444.779
BODC Series Reference 442732
 

Time Co-ordinates(UT)

Start Time (yyyy-mm-dd hh:mm) 1996-07-12 16:10
End Time (yyyy-mm-dd hh:mm) 1996-07-24 13:30
Nominal Cycle Interval 600.0 seconds
 

Spatial Co-ordinates

Latitude 56.46130 N ( 56° 27.7' N )
Longitude 8.18720 W ( 8° 11.2' W )
Positional Uncertainty 0.1 to 0.5 n.miles
Minimum Sensor Depth 148.5 m
Maximum Sensor Depth 148.5 m
Minimum Sensor Height 0.5 m
Maximum Sensor Height 0.5 m
Sea Floor Depth 149.0 m
Sensor Distribution Fixed common depth - All sensors are grouped effectively at the same depth which is effectively fixed for the duration of the series
Sensor Depth Datum Sea floor reference - Depth measured as a height above sea floor but converted into a depth relative to the sea surface according to the same datum as used for sea floor depth (applicable to instrument depths not bathymetric depths)
Sea Floor Depth Datum Instantaneous - Depth measured below water line or instantaneous water body surface
 

Parameters

BODC CODE Rank Units Short Title Title
AADYAA01 1 Days Date(Loch_Day) Date (time from 00:00 01/01/1760 to 00:00 UT on day)
AAFDZZ01 1 Days Time(Day_Fract) Time (time between 00:00 UT and timestamp)
PRSTPS01 1 Decibars TotPressSeaFL Pressure (measured variable) exerted by the water body plus atmosphere by fixed in-situ pressure sensor
TEMPPR01 1 Degrees Celsius Temp Temperature of the water body
 

Definition of Rank

  • Rank 1 is a one-dimensional parameter
  • Rank 2 is a two-dimensional parameter
  • Rank 0 is a one-dimensional parameter describing the second dimension of a two-dimensional parameter (e.g. bin depths for moored ADCP data)

Problem Reports

No Problem Report Found in the Database


Data Access Policy

Open Data supplied by Natural Environment Research Council (NERC)

You must always use the following attribution statement to acknowledge the source of the information: "Contains data supplied by Natural Environment Research Council."


Narrative Documents

Aanderaa Bottom Pressure Recorder Models 5 and 6

The water level recorder models 5 and 6 are self-contained, high precision instruments for recording of the water level by precise measurement of hydrostatic pressure. The pressure sensor consists of an oscillating quartz crystal which shifts frequency with the force applied to it. Temperature is measured by a Fenwall thermistor. Data are stored on magnetic tape

Specifications

Pressure

Oscillator Frequency 36-40 kHz
Resolution 0.001% of full scale
Integration 40 seconds

Ranges available:

WLR5 0-100psi, 0-400psi (standard), 0-900psi
WLR6 0-5000psi (deep water version)

Temperature

The thermistor is a Fenwall GB32JM19

Range -3 °C to +35 °C
Accuracy ±0.1 °C
Resolution 0.04 °C
Response Time 2 minutes

Offshore Sea Floor Pressure Data Screening Carried Out by BODC

BODC screen both the series header qualifying information and the parameter values in the data cycles themselves.

Header information is inspected for:

  1. Irregularities such as suspect values.

  2. Inconsistencies between related information, for example depths of meter and sea bed; times of mooring deployment and for start/end of data series; length of record or number of data cycles, the cycle interval, the clock error and the period over which accrued; originator's comments on meter/mooring performance, data quality and parameters measured and the parameters actually present in the data cycles. Documents are written by BODC highlighting irregularities which cannot be resolved.

Data cycles are inspected via time series plots of parameters. These plots undergo intrinsic and extrinsic screening to detect suspect values within the data cycles themselves and inconsistencies when compared with adjacent data sets. Values suspected of being of non oceanographic origin may be tagged with the BODC flag denoting suspect value.

The following types of irregularity, each relying on visual detection in the time series plot, are amongst those which may be flagged as suspect:

  1. Spurious data at the start or end of the record.

  2. Obvious spikes of non oceanographic origin.

  3. A sequence of constant values in consecutive data cycles.

If a large percentage of the data are affected by irregularities, deemed abnormal, then instead of flagging the individual suspect values, a caution may be documented.

Inconsistencies between the characteristics of the data set and those of its neighbours, as for example between the maximum and minimum values of the parameters (spikes excluded) are, where necessary, documented.

This intrinsic and extrinsic screening of the parameter values seeks to confirm the qualifying information and the source laboratory's comments on the series. In screening and collating information, every care is taken to ensure that errors of BODC making are not introduced.

Proudman Oceanographic Laboratory Pressure Recorder Data Processing

The data are converted to scientific units using factory calibrations. The date and time channel is adjusted to take account of the 40 second integration interval. The integrity of the time stamps is verified by tidal analysis.


Project Information

Land Ocean Interaction Study (LOIS)

Introduction

The Land Ocean Interaction Study (LOIS) was a Community Research Project of the Natural Environment Research Council (NERC). The broad aim of LOIS was to gain an understanding of, and an ability to predict, the nature of environmental change in the coastal zone around the UK through an integrated study from the river catchments through to the shelf break.

LOIS was a collaborative, multidisciplinary study undertaken by scientists from NERC research laboratories and Higher Education institutions. The LOIS project was managed from NERC's Plymouth Marine Laboratory.

The project ran for six years from April 1992 until April 1998 with a further modelling and synthesis phase beginning in April 1998 and ending in April 2000.

Project Structure

LOIS consisted of the following components:

Marine Fieldwork

Marine field data were collected between September 1993 and September 1997 as part of RACS(C) and SES. The RACS data were collected throughout this period from the estuaries and coastal waters of the UK North Sea coast from Great Yarmouth to the Tweed. The SES data were collected between March 1995 and September 1996 from the Hebridean slope. Both the RACS and SES data sets incorporate a broad spectrum of measurements collected using moored instruments and research vessel surveys.


LOIS Shelf Edge Study (LOIS - SES)

Introduction

SES was a component of the NERC Land Ocean Interaction Study (LOIS) Community Research Programme that made intensive measurements from the shelf break in the region known as the Hebridean Slope from March 1995 to September 1996.

Scientific Rationale

SES was devoted to the study of interactions between the shelf seas and the open ocean. The specific objectives of the project were:

Fieldwork

The SES fieldwork was focussed on a box enclosing two sections across the shelf break at 56.4-56.5 °N and 56.6-56.7 °N. Moored instrument arrays were maintained throughout the experiment at stations with water depths ranging from 140 m to 1500 m, although there were heavy losses due to the intensive fishing activity in the area. The moorings included meteorological buoys, current meters, transmissometers, fluorometers, nutrient analysers (but these never returned any usable data), thermistor chains, colour sensors and sediment traps.

The moorings were serviced by research cruises at approximately three-monthly intervals. In addition to the mooring work this cruises undertook intensive CTD, water bottle and benthic surveys with cruise durations of up to 6 weeks (3 legs of approximately 2 weeks each).

Moored instrument activities associated with SES comprised current measurements in the North Channel in 1993 and the Tiree Passage from 1995-1996. These provided boundary conditions for SES modelling activities.

Additional data were provided through cruises undertaken by the Defence Evaluation and Research Agency (DERA) in a co-operative programme known as SESAME.


Data Activity or Cruise Information

Data Activity

Start Date (yyyy-mm-dd) 1996-07-12
End Date (yyyy-mm-dd) 1996-07-24
Organization Undertaking ActivityProudman Oceanographic Laboratory (now National Oceanography Centre, Liverpool)
Country of OrganizationUnited Kingdom
Originator's Data Activity IdentifierPOLRIG#779
Platform Categoryfixed benthic node

Proudman Oceanographic Laboratory Moored Instrument Rig #779

This rig was deployed as part of the LOIS Shelf-Edge Study at site S140E.

Rig position: 56° 27.68'N 08° 11.23'W
Deployed: 12 Jul 1996 15:58
from RRS Challenger (cruise CH128A)
Recovered: 24 Jul 1996 13:36
onto RRS Challenger (cruise CH128A)

Instruments deployed on the rig

Height above
Sea Bed
Instrument
0.5m Aanderaa Bottom Pressure Recorder (#444)
0.5m RDI Acoustic Doppler Current Profiler (#1148)

Other Series linked to this Data Activity - 477191

Cruise

Cruise Name CH128A
Departure Date 1996-07-10
Arrival Date 1996-07-26
Principal Scientist(s)John H Simpson (University of Wales, Bangor School of Ocean Sciences)
Ship RRS Challenger

Complete Cruise Metadata Report is available here


Fixed Station Information

Fixed Station Information

Station NameLOIS(SES) S140E
CategoryOffshore location
Latitude56° 27.50' N
Longitude8° 11.07' W
Water depth below MSL146.0 m

LOIS (SES) Mooring and CTD Site S140E

Site S140E was a fixed station where moorings were deployed during the Land-Ocean Interaction Study (LOIS) Shelf Edge Study (SES). It was also one of fourteen CTD sites on repeat section S, across the Hebridean Slope, occupied by cruises between March 1995 and September 1996.

Instrument Deployment History

The following tables summarise the instruments deployed at this site for which data may be available.

1995

Mar Apr May Jun Jul Aug Sep Oct Nov Dec
CM                    
BPR                    
ADCP                    
TChn                    

1996

Jan Feb Mar Apr May Jun Jul Aug
CM             a a
BPR             a a
ADCP             a a
TChn             a a

Each different letter in the tables above corresponds to an individual instrument record

Glossary

Note

  1. Transmissometers may have been fitted to some of the current meters.
  2. Only periods for which useful data were returned are shown.

Other Series linked to this Fixed Station for this cruise - 438978 442492 444449 477191 477375 477387


BODC Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Flag Description
Blank Unqualified
< Below detection limit
> In excess of quoted value
A Taxonomic flag for affinis (aff.)
B Beginning of CTD Down/Up Cast
C Taxonomic flag for confer (cf.)
D Thermometric depth
E End of CTD Down/Up Cast
G Non-taxonomic biological characteristic uncertainty
H Extrapolated value
I Taxonomic flag for single species (sp.)
K Improbable value - unknown quality control source
L Improbable value - originator's quality control
M Improbable value - BODC quality control
N Null value
O Improbable value - user quality control
P Trace/calm
Q Indeterminate
R Replacement value
S Estimated value
T Interpolated value
U Uncalibrated
W Control value
X Excessive difference

SeaDataNet Quality Control Flags

The following single character qualifying flags may be associated with one or more individual parameters with a data cycle:

Flag Description
0 no quality control
1 good value
2 probably good value
3 probably bad value
4 bad value
5 changed value
6 value below detection
7 value in excess
8 interpolated value
9 missing value
A value phenomenon uncertain